Composite railway-track member



Patented Oct. 7, 1924.

v UNITED .STATES PATENT, OFFICE.

JAMES H. cnrrcnnrr, or BAYSIDE, NEW YORK. ASSIGNOR T THE OXWELD nun .1Roan SERVICE COMPANY, A conronn'rron or DELAWARE COMPOSITE RAILWAY-TRACK-IMEMBER AND COMPOSITION FOR, JPROIDUCING T HE a SAME.

No Drawing. Application fi led July29, 1922, Serial No. 578,499. RenewedSeptember 8, 1924.

T 0 all whom it may concem.

Be it known that I, JAMES H. CRITCHETI,

a citizen of the United States, residin at Bayside, in the county ofQueens and tate of New York, have invented certain new and usefulImprovements in Composite Railway-Track Members-and Compositions forProducing the Same, of which the following is aspecification.

This invention relates to composite railway track members having a bodyportion of one composition, which is at least in part cased, sheathed orarmored With another composition'of greater hardness and higherresistance to wear. The invention also comprises novelcompositionsuseful for 'producing casings or armor of'the kind men-. tioned on trackmembers and other members subjected to similar service.v V

The material for railway rails, frogs, switches and crossings, shouldhave the strength and toughness necessary in struc-v tural memberstogether with eat hardness and resistance to wear to ena le it towithstand the abrasion and pounding to which it is subjected by therolling stock. No single material has been found which combines thesequalities with suflicient cheapness and workability, and a fairly highcarbon steel has been universally adopted as a compromise. While surfacedeterioration necessitates expensive replacements, failure of the bodyof the rail by fracture is'apt to cause disastrous accidents. For

I 85 this reason the carbon content has been limited to prevent anydangerous brittleness and the great majority of rail troubles are amatter of mere surface deterioration.

I Several expedients have been proposed for 40 producing composite trackmembers having body and surface portions particularly adapted to theirrespective special requirements. The restoration of wearing surfacesWhich had been more or less damaged, by 4 providing a new surface of amaterial particularly fitted to withstand surface wear,

I has been of much interest, and thepossibility of filling in orbuilding up the worn surfaces with a suitable metal fused by theelectric are or by the blow-torch has attracted special attention. Thepresent inventionrelates to processes of-this nature. For .the sake ofbrevity, metal which is deposited in molten form on a member for thepurpose described will be referred to as added metal, while the materialof the member which receives such addition will be termed the basemetal.

Steel of higher carbon content than the body of' the rail has been triedas added metal, but the increased carbon makes its deposition inhomogeneous form a diflicult matter. Furthermore, in carbon steels, thebrittleness increases with hardness, so that While deterioration bydeformation or abrasion may be reduced, deterioration by spawlin-g,chipping and cracking becomes a serious objection. I

It has also been proposed to usea manganese steel containing, say, 14%of manganese for such purposes. This also has not proved entirelysatisfactory, for while manganese steel is highly resistant to wearunder certain conditions, a heat-treatment is necessary to develop thisproperty and if the appropriate heat-treatment is applied to the addedmanganese steel, the body of the rail, being carbon steel, is rendereddangerously brittle. Furthermore, manganese steel is not hard enough toresist in a wholly satisfactory manner such impacts as certain kinds oftrack members receive. Another difficulty experienced when manganesesteel is used as the added metal is explained by the fact that steelscontaining certain percentages of manganese, less than the manganesecontent of the added material, have properties which render them unfitfor use in any part of a rail. or the like, and these undesiredcompositions may be formed at the junctureof the added and base metals,due to dilution of the manganesecontent of the added metal by thesuperficially fused base.

'I have found that a better casing or armoring material for worn or newtrack members or the like may be produced by using chromium as ahardening agent in the v steel added, a considerable amount of carbonbeing also incorporated. The chromium content should preferably be notmuch below 1.0% and may be increased to 3.0% or more. The carbon contentmay be as much as 1.0%, but it is preferred to keep the carbon at aconsiderably lower figure and to secure the necessary hardness andtoughness by suitable additions of chromium. F urthermore, I have foundthat a reciprocal relation between the carbon and chromium iospercentages gives thebest results, this relation being sufiicientlyillustrated by the following examples:

lit themaximum chromium addition (about 3%) is used, the carbon shouldpref- 'erably not exceed 0.5%; while if the carbon is as low as 0.2%,the chromium content should be between1.5-3.0%. With a carbon contentapproaching the maximum (for example 1%), the chromium should preterablynot exceed 1.5%. My preferred chromium range is from .75% to 1.50% withcarbon between 0.2% and 0.6%.

y 1 also find it desirable to include a considerable quantity of siliconin the metal which is tobe melted andbuilt up on the in weldingoperations. The manganese content of the welding metal may be from .50%

to 1.75% and the silicon from .3%' to 1.50%. Excellent results have beenobtained with manganese between .80% and 1.0%, and sili-' conbetween'.50% and .75%. In general, a part of the manganese. will persistin the filled-in metal, where it probably has a favorable action as analloyed constituent.

The best results appear to be obtained when the percentage of manganeseis somewhat greater than the percentage of silicon, for example,approximately in the ratio'of 1.5

' or 2 to 1.

A filling metal having carbon 0.35% to 0.415%, chromium 1.0% to 1.2%,silicon 0.5%

to 0.6% and manganese 0.9% to 1.1%, has

given excellent results.

The chromium-containing compositions disclosed herein produce a case orarmor which in hardness, toughness, and resistance to wear, excels thecarbon steel base on which it is laid. The added metal is free from thebrittleness of carbon steels of comparable hardness, and is very mucheasier to manipulate. The chromium compositions are harder than themanganese steels which have been used for similar purposes, andtherefore are less deformed by impact. They require no heat-treatmentand form no compositions of undesirable properties with the base'metal.

While various specific compositions are described herein for purposes ofillustration, it will be understood that the invention is subject tomany modifications in accordance with the principles disclosed, and isonly limited by the appended claims.

Welding rods or the like comprising alloys of the type disclosed hereinare described and claimed in .my application Serial No. 690,089, filedFebruary 1, 1924;.

ll claim:

1. A railwaytrack member comprising a steel base armored'with an alloysteel which,

without heat-treatment, is harder and more resistant to wear than saidsteel base.

2. The invention according to claim 1 in which the alloy steel of thearmor contains a substantial amount of chromium.

8. The invention accordingto claim 1 in which the alloy steel of thearmor contains a substantial amount of chromium, less than 3%.

4. The invention according to claim 1 in which the alloy steel of thearmor contains between 0.75% and 1.50% of chromium and between 0.2% and0.6% of carbon.

In testimony whereof,-l afiix my signature.

